Ordered/unordered list doesn't add new list item on newline (Android/Chrome)

When using Android/Chrome, and adding items to a list, the "newline" (return) key doesn't cause a new list item to appear, but instead the current list item is continued over 2+ lines.

##### Steps to Reproduce

1. Use your Android phone and open Chrome
2. Go to trix-editor.org
3. Go to a blank line in the Trix editor input field
4. Tap/click the "unordered list" format button
5. You'll see a bullet appear as you now write the first list item
6. Write some text in the first list item
7. Tap/click newline (return)
8. A new list item will not appear! :-( [yet it does in Chrome on Mac OS/X]

##### Details

* Trix version: latest
* Browser name and version: Chrome (latest)
* Operating system: Android

Start by reproducing the issue in the Trix editor input on trix-editor.org using Android/Chrome, then compare the unordered-list button and newline behavior with Chrome on macOS. Done means pressing return after text in a list consistently creates a new list item on Android/Chrome without regressing desktop behavior.

Written by the indexing model from the issue text.